Theoretical insight into the doubly antiaromatic carbon allotrope cyclo[16]carbon

A new carbon allotrope, cyclo[16]carbon (C16), has recently been successfully synthesized. It is hypothesized to exhibit double antiaromatic properties owing to the 4n pi electrons. Theoretical calculations are a feasible method for systematically studying the structures and properties of unstable antiaromatic molecules. The results show that C16 has a planar structure characterized by alternating long and short bonds with D8h, and a strong antiaromatic characteristic originates from the two perpendicular pi systems. We performed an extensive comparative analysis of C16 and the aromatic cyclo[18]carbon, C18. This study offers valuable insight into the structural and electronic characteristics of C16 and could inspire innovative applications and avenues for its utilization in various fields. C16 has a planar structure characterized by alternating long and short bonds with D8h, and its strong antiaromatic characteristic originates from the two perpendicular pi systems.